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Who has one with gm serpentine belt setup and what brand is it?
made my own. Most don't clear properly unless you purchase a un-welded version so you can adjust as required.
After installing to tell the truth it really didn't make much difference. There were times when I loosened the bar while making alignment adjustments and forgot to tighten the bar. I could never tell it wasn't connected. Drove for a few weeks and never noticed.
Were I was hoping to notice the most improvement was at the track, but sadly for my car (78) it really didn't make any changes.
I am using the complete VB&P street and slalom setup with poly bushings everywhere. SPC Upper control arms. Poly engine mount on the driver side with rubber on the passenger side.
Last edited by cagotzmann; 05-28-2017 at 11:56 PM.
IF you don't notice much difference from a properly installed spreader bar, I suggest you put on decent wheels/tires....I noted the entire front end tightened up a LOT when it was added, now of course I have rack steering, and larger tires 255/50/17 in front 275/50/17 rear, plastic spring in rear, urethane all over,
IF you don't notice much difference from a properly installed spreader bar, I suggest you put on decent wheels/tires....I noted the entire front end tightened up a LOT when it was added, now of course I have rack steering, and larger tires 255/50/17 in front 275/50/17 rear, plastic spring in rear, urethane all over,
I noticed an immediate difference as soon as I installed my Speedirect spreader after the installation as soon as I pulled out of the driveway!
The whole front end felt more connected together and to the rear suspension, noticeable reduction in squeaks in the cabin, tighter steering response, and more predictable handling....the car simply goes where it is pointed.
If you cannot feel the difference with the spreader bar connected, something is not right, especially with a body on frame chassis like in the C3's which is know to flex MUCH on it own without a spreader bar since the actual fiberglass body adds no structural support to prevent the frame from flexing.
I too have poly everywhere with a modified suspension on my C3 and the spreader bar makes a noticeable difference:
Front:
Speedirect spreader bar
Custom blueprinted/rebuilt OEM steering box with Olite steering shaft bushing eliminating all steering play
Poly upper and lower control arm bushings
550 springs 1.5 inch shorter than stock gymkhana springs
OEM 1 1/8 front sway bar with poly mounting and endlink bushings
Bilstein HD's with poly bushings
255/45/17 ZR ultra high performance summer only tires
Rear:
360 VBP composite monospring with poly end cushings
Competition adjustable struts with Heim joints..no bushings
GM Style 3/4 inch rear sway bar with poly mounting bushings
Bilstein Sports
255/50/17 ZR ultra high performance summer only tires
I had the L-82 355 out yesterday, and between the 425+ Gross HP rebuilt/upgraded engine, superb handling, and incredibly comfortable ride (firm but not at all harsh), the car is simply a blast to drive and so different from what it was when brand new BUT still so much a C3 corvette with better/upgraded components throughout without loosing the C3 basic design and feel..Just need a 5 speed with .64 OD and it would be almost perfect....
Lastly, I also have strut tower braces on 2 of my more modern cars which are unibody frames and much stiffer than the C3 chassis and both have strut tower braces on them. You can also feel the difference the bracing makes on these cars
2001 Pontiac Grand Prix FWD with BOTH front and rear strut tower braces
2008 Chrysler 300 with a VERY HEAVY duty 3 inch front strut tower brace that bolts over the struts curves to the back of the engine where it is bolted to the factory firewall brace and over to the other strut tower. This frame brace made a HUGH difference in the steering response, stiffened the ride, tightened the chassis, improved the solidness of the handling,...worth all of the $450 that it cost from Mopar...
Unless you are driving a roll cage racing type chassis/frame car, I find it hard to believe that a Spreader bar connecting the front suspension together would not be felt noticeably on a C3. As stated above, I have never had the experience of tightening up the frame/chassis where the result is not very noticeable...........
noticeable reduction in squeaks in the cabin, tighter steering response, and more predictable handling....the car simply goes where it is pointed.
I understand what you are saying, but until you do a blind test you won't really now how your mind is playing with you. We all believe everything thing we do is for the better. So therefor if we add something to our car it is always for the better.
I remember someone on the forum removing 1 side of the spreader bar and had a video of the movement. Their wasn't enough movement to effect the alignment of the car and therefor have any effect on tighter steering response, predictable handling or simply goes where it is pointed. This is very subjective.
Here is what I would look for. Changes in camber / caster / toe during corner entry / apex / corner exit with and without the spreader bar. etc. I don't have anything to measure this. The best I can do is measure G's and speeds. G's is the limit of the tires and alignment settings so I am not sure I can measure the difference.
But on the good side for installing one. It does support the frame for problems of cracking / breaking welds / and supporting the frame. It will also improve in rattles / squeaks when 1 tire hits a bump / pot hole.
Is there a good reason not to have one. Yes if it cost $1000+.
Because it is cheap to install and helps save the frame and can reduce rattles and squeaks its well worth it.
Knowing that your car doesn't rattle like a old clunker makes people feel it handles better which is subjective at best.
The biggest benefit for the street car is in body flexing which produces car noises, but for handling driving around a corner and 10-20 MPH I don't get it.
So the question is if a spreader bar cost $1000.00 how many people would do it, and still say WOW the best mod I ever done.
What about measurements between control arm mounts? I want to make sure mine are correct.
What I did was make the brackets for the control arms first. Install the hemi joints and measure the difference for your car.
The mock up brackets where made from Styrofoam and I used a wooden dowel to simulate the bar.
Every car will vary based on the frame stability / age.
I allowed enough adjustment for 3/4" both sides to allow for camber / alignment changes. I also wanted to make sure that a least 1/2" of thread was always in the bar of the hemi joints. I believe the hemi joints have about 1.25" of threads total.
You will also need to loosen the bar every time you need change the alignment for camber caster as the bar will restrict movement of the upper arms.
Also make sure you can get a socket / wrench on the control arms and allow you to tighen / loosen the bolt, or you will never be able to tighten to spec's
The bar itself I had a machine shop make the threads for the hemi joint ends. The bar is aluminum and 1 side is left hand thread and the other side right hand thread.
What I did was make the brackets for the control arms first. Install the hemi joints and measure the difference for your car.
The mock up brackets where made from Styrofoam and I used a wooden dowel to simulate the bar.
Every car will vary based on the frame stability / age.
I allowed enough adjustment for 3/4" both sides to allow for camber / alignment changes. I also wanted to make sure that a least 1/2" of thread was always in the bar of the hemi joints. I believe the hemi joints have about 1.25" of threads total.
You will also need to loosen the bar every time you need change the alignment for camber caster as the bar will restrict movement of the upper arms.
Also make sure you can get a socket / wrench on the control arms and allow you to tighen / loosen the bolt, or you will never be able to tighten to spec's
The bar itself I had a machine shop make the threads for the hemi joint ends. The bar is aluminum and 1 side is left hand thread and the other side right hand thread.
I had an alignment done before and the set the caster and camber as good as they could due to lack of shims in the car. I have since lowered it, added global west upper arms and know it will need a bar to gain the camber back it should have.
What about measurements between control arm mounts? I want to make sure mine are correct.
If you make your own the measurement will vary. With my setup the bar is 19", but a someone else shows his setup its not the same. So start with the brackets add the joints and then measure to fit.
Iknow it will need a bar to gain the camber back it should have.
Not sure how the bar helps this. The bar is not used to widen the a-arms or fix a sagging frame. It is only there to support the current dimension from further sagging and flexing. If you cannot get enough caster the new arms will help some. If you cannot get the proper camber on the front (Near 0) then you have a frame problem that the bar will not fix.
What was the best camber they could get ?
I have SPC Upper arms which let you adjust for both camber and caster. My arms are set with 0 shims to provide 0 camber with 4.4 caster. When I go to the track I add 2 shims to get 1.3 camber up front. and adjust toe as required. Adding camber changes toe settings.
Not sure how the bar helps this. The bar is not used to widen the a-arms or fix a sagging frame. It is only there to support the current dimension from further sagging and flexing. If you cannot get enough caster the new arms will help some. If you cannot get the proper camber on the front (Near 0) then you have a frame problem that the bar will not fix.
What was the best camber they could get ?
I have SPC Upper arms which let you adjust for both camber and caster. My arms are set with 0 shims to provide 0 camber with 4.4 caster. When I go to the track I add 2 shims to get 1.3 camber up front. and adjust toe as required. Adding camber changes toe settings.
I was using a setup I wasnt famailar with so not sure I set it up correctly but it showed -3.5* LF and -1.4 RF Camber, 3.0 LF and 4.4 RF Camber, toe .05 LF and .04 RF. The car is stable in flat straight road, crowns and change in pavement lines make it interesting and "darty" or "twitchy".
The op may not have noticed a big difference because of his urethane motor mounts.those should help tighten up the front end a bit too.
but blind test or not I contend anyone blind or not could feel the difference going out my driveway.I expected to drive the car a couple weeks and think yeah maybe it helped,but it was noticible instantly.
Mr. Cagotzman is suggesting that anyone who has installed a spreader bar and says it made a difference is imagining it. I disagree. I put it on, it made a difference.
Mr. Cagotzman is suggesting that anyone who has installed a spreader bar and says it made a difference is imagining it. I disagree. I put it on, it made a difference.
No I am suggesting that what you perceive as making a difference is simply a reduction in rattle / noises / firmness in the frame, and not a handling improvement.
It is simply based on the bar doesn't effect any major changes to the alignment stability on the street and therefor effect the handling.
Never said it didn't do anything at all, but claims of improved handling while cornering / response on turn in etc, etc, on the street it is nothing more than the extra confidence you may have and driving a corner faster than you would normally. This alone gives you a extra rush that makes you feel good.
Now driving on a road course with super sticky tires at the limit of the tires, you will have a better chance at holding the alignment in the corners with a bar vs without one.
eg at my local track I get a max of ~ 1.15 g's in some corners. Not a chance I would attempt this on any street road. So for me its hard to get the WOW factor on the street.
The best benefit of the bar is the reduce body flexing / rattles / noises this doesn't give you confidence when your car rattles. With the bar installed and the noises reduced it just feels better to the ears and mind.
The blind test would show what our mind imagines and what is real. I would bet most wouldn't tell the difference in other than noise alone. And on a smooth road would never tell the difference with or without one.
It is still worth installing because the benefit vs cost is great. I have never heard anyone be disappointed installing one. If it makes you feel better about your car, its worth it.
05-28-2017, 11:48 PM
